Added the keyboard tutorial

Author: liamrahav

README.md

@@ -50,7 +50,7 @@ Simply head to your terminal and type in `pip install cocos` or `sudo pip instal
 
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-From here you should be read to start reading through the samples and trying out the concepts yourself. I group the the code by difficulty level, so I recommend in the `basics` folder and working your way up.
+From here you should be read to start reading through the samples and trying out the concepts yourself. I group the the code by difficulty level, so I recommend starting in the `basics` folder and working your way up.
 
 It's important to note that `basics` does not mean Python basics! You should at least have a basic grasp on writing object oriented code before trying to jump into Cocos2D Python!
 

basics/actions.py

@@ -12,10 +12,12 @@
 
 
 # Here I make a class that extends cocos' ColorLayer class
+# This type of layer is different because it has a background color! (awesome right?)
 class Actions(ColorLayer):
     # When I initialize it I need to pass in an RRGB colour value so it can set the ColorLayer's background
+    # I grabbed the Peter River colour (#3498db) from http://flatuicolors.com for this sample
     def __init__(self):
-        super(Actions, self).__init__(52, 52, 73, 94)
+        super(Actions, self).__init__(52, 52, 152, 219)
 
         # I initialize a sprite using the cocos sprite.Sprite class
         # Change the path below to whatever your sprite image is

basics/basics.md

@@ -6,3 +6,6 @@ Here is the order which the tutorial follows:
 1.  Getting Started (getting_started.py)
 2.  Adding Actors (actors.py)
 3.  Basic Actions (actions.py)
+4.  Keyboard Input (keyboard.py)
+5.  Mouse Input (mouse.py)
+6.  Applying User Input (input.py)

basics/keyboard.py

@@ -0,0 +1,82 @@
+# Same imports once again
+
+import cocos
+from cocos.text import Label
+from cocos import scene
+from cocos.layer import Layer
+from cocos.director import director
+from cocos.sprite import Sprite
+
+# Except for this import. This import, from Pyglet (one of the dependencies of cocos), is to recognize keyboard codes
+from pyglet.window.key import symbol_string
+
+
+# Similar starting code to before with one exception
+class KeyboardInput(Layer):
+    # You need to tell cocos that your layer is for handling input!
+    # This is key (no pun intended)!
+    # If you don't include this you'll be scratching your head wondering why your game isn't accepting input
+    is_event_handler = True
+
+    def __init__(self):
+        super(KeyboardInput, self).__init__()
+
+        # Let's make a Label like we did in the HelloWorld sample to show the keys being pressed
+        # We will write code to append the key being pressed further down in the file
+        self.label = Label("Keys: ",
+                      font_name = "Helvetica",
+                      font_size = 32,
+                      anchor_x = "center",
+                      anchor_y = "center")
+        self.label.position = 320, 240
+
+        # Here I make a variable to store the keys being pressed
+        # set() creates a new set object.
+        # A set object is an object built into Python that stores things in, you guessed it, sets
+        # You can call the add() and remove() methods to modify the contents of a set
+        self.keys_being_pressed = set()
+
+        # Next I run my update_text function that I write further down in the file
+        self.update_text()
+
+        # And lastly I add my label to the layer!
+        self.add(self.label)
+
+    # This is the function that updates the label
+    def update_text(self):
+        # Here I get the name of the key
+        # This line requires a bit of explanation
+        # Essentially, I look at the key being pressed (which I set in a function further down)
+        # And I match it up to the appropriate symbol for that string
+        # So if the "T" key and the left "Shift" key were being pressed, this line would recognize their respective code,
+        # And it would set the variable to "T", "LSHIFT"
+        key_names = [symbol_string(k) for k in self.keys_being_pressed]
+
+        # This line sets the text to the indicated string, joining in the key names until there are no more keys indicated
+        text_for_label = "Keys: " + ", ".join(key_names)
+
+        # This code is a bit lengthy, but essentially I'm just accessing the text element from the Label object
+        self.label.element.text = text_for_label
+
+    # This function is once of the default Cocos functions. I overload it and add my own code
+    # By default this function just passes, but I make it actually do stuff!
+    def on_key_press(self, key, modifiers):
+        # By stuff I mean updating the keys_being_pressed variable with the key being passed in through Cocos
+        self.keys_being_pressed.add(key)
+        # Then I simply run my update text method to make sure the string gets updated
+        self.update_text()
+
+    # This function is also a default Cocos function!
+    # I have to remember to update both the keys currently pressed and the string when they release a key
+    # You can try commenting this out to see what happens when you hit a key and let go without this piece of code
+    def on_key_release(self, key, modifiers):
+        # Same code as before, except I remove instead of add the key
+        self.keys_being_pressed.remove(key)
+        self.update_text()
+
+# And then I use the same code you're used to seeing to run the layer
+director.init()
+director.run(scene.Scene(KeyboardInput()))
+
+
+